Okay, he's completely normal. That's incredibly frustrating but it's true. He was "fine" in the hospital because it was a new place. But now that he realizes the baby is here to stay, his "normal" is no longer normal. A lot of kids verbalize it by telling their parents to send the baby back or to put it back in Mommy's tummy, others just completely pretend to be in love but are freaked out about the changes in their own lives.
He might adore her because he gets praised every time he is sweet to her and gentle with her. But she's feeding on demand, as she should be, so he has figured out that her demands/needs come first. He knows that crying gets her attention, and crying brings people into her room. Therefore, crying = her room + a place to be praised + a place to be where the action is.
So, if some things are different, then everything is different. He's not going to use the regular plates either because everything is different or because the baby doesn't, or both. She gets what she needs whenever she feels like it, and he's on a schedule and therefore "not special."
I understand the desire to keep him in his routine, but it's not working. He sees that your routine is different, so why shouldn't his be, you know? So you have to decide where you can be flexible and where you cannot. If YOU can, try to eat what he eats and when he eats. Make it YOUR special time with him. If possible, make the baby wait (or have someone else deal with her) and let him get what he needs when he wants it. I know you can't always do that, but if you can label things as your special time with him, or the big boy time, and even on occasion make reference to the fact that the baby is demanding/frustrating/exhausting but won't always be, it might help.
Also, he's in a new role - big brother - so he may think that all the old routines and foods are for little boys and not for the good big bro he has become.
Hang in there. It's very difficult but it just takes time to get into some new routines. And as I said, her very presence and your relationship with her makes things all new - so all old bets are off.
If she can give him presents for Chanukah or Christmas, that would be good. Having her GIVE rather than just TAKE might help. Otherwise, it's just a question of time. I'm sorry there's not much of a better answer!